Engineering a Design System

While plenty is said about design system theory, organizational adoption, and visual design, you won’t get very far without solid engineering practices, sound architecture, and the right technologies.

We’ll take a tour through the engineering of TELUS digital’s React-based design system developed over the past year, examining technologies such as CSS Modules; testing practices; architectural decision points; and strategies for scaling to dozens of teams and hundreds of users.

Whether you are at a small or large scale, just starting or far along with a design system, you can immediately apply the lessons and technologies from this talk to your own work.

Transcript

1. Engineering
   a
   Design System
   

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2. Design systems
   Style guide?

   Component library?

   UI toolkit?
   }close enough
   

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3. Make designers and developers more produc

   Consistent end user experience
   Why?
   

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4. h"ps://www.telus.com
   | Design System
   

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5. | Design System
   React Sketch
   

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6. Engineering for stability
   by crea(ng inten(onal APIs and

   tes(ng first and o5en.
   Engineering for scale ↔
   by automa(ng documenta(on and
   op(mizing package distribu(on.
   

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7. 

   // Button.scss
   .button {
   padding: 1rem;
   border-radius: 4px;
   color: white;
   }
   .button--primary {
   background-color: $color-primary;
   }
   .button--secondary {
   background-color: $color-secondary;
   }
   

   
   Shop now
   
   
   Learn more
   
   class Button extends React.Component {
   render() {
   // a branded HTML button
   }
   }
   Design system Applica8on
   Output
   

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8. 

   // Button.scss
   .button {
   padding: 1rem;
   border-radius: 4px;
   color: white;
   }
   .button--primary {
   background-color: $color-primary;
   }
   .button--secondary {
   background-color: $color-secondary;
   }
   

   // MySquareButton.scss
   

   .button {
   border-radius: 0;
   color: black;
   }
   .my-square-button {
   background-color: hotpink;
   }
   

   className=“my-square-button">
   Find a store
   
   class Button extends React.Component {
   render() {
   // a branded HTML button
   }
   }
   Design system Applica8on
   

   // Button.scss
   .button {
   padding: 1rem;
   border-radius: 4px;
   color: white;
   }
   .button--primary {
   background-color: $color-primary;
   }
   .button--secondary {
   background-color: $color-secondary;
   }
   Output
   

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9. h"ps://github.com/css-modules/css-modules
   

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10. // Button.scss
    .button {
    // core button styles
    }
    .primary {
    composes: button;
    background-color: $color-primary;
    }
    .secondary {
    composes: button;
    background-color: $color-secondary;
    }
    import styles from './Button.scss'
    class Button extends React.Component {
    render() {
    return (
    
    {this.props.children}
    
    )
    }
    }
    

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11. // Button.scss
    .button {
    // core button styles
    }
    .primary {
    composes: button;
    background-color: $color-primary;
    }
    .secondary {
    composes: button;
    background-color: $color-secondary;
    }
    import styles from './Button.scss'
    class Button extends React.Component {
    render() {
    return (
    
    {this.props.children}
    
    )
    }
    }
    // compiled Button.css
    .TDS_Button__button___2kyCB {
    ...
    }
    

    .TDS_Button__primary___3Xb72 {
    ...
    }
    .TDS_Button__secondary___2qhCP {
    ...
    }
    

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12. 

    
    Shop now
    
    
    Learn more
    
    

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13. Accessibility Tes8ng
    

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14. 

    $ yarn test:e2e @tds/core-button
    yarn run v1.5.1
    $ node scripts/e2e.js
    Started chromedriver
    [Components Spec] Test Suite
    ================================
    Running: @tds/core-button
    ✔ Element was visible after 31 milliseconds.
    ✔ Passed [ok]: 9 aXe Tests Passed
    ✖ Failed [fail]: (Elements must have sufficient color contrast [class="TDS_Flexbox-modules__row___DL6tZ TDS_BaseButton-modules__centered___3Xkio
    TDS_Borders-modules__rounded___1Qg-s">Submit]) - expected "https://
    dequeuniversity.com/rules/axe/2.6/color-contrast?application=axeAPI" but got:
    "policy violation"
    at endReadableNT (_stream_readable.js:1101:12)
    ✖ #app passes accessibility scan - expected "true" but got: "false"
    at Object.checkAccessibility (/Users/ryanoglesby/Projects/telus-digital/tds/
    e2e/commands/checkAccessibility.js:4:35)
    FAILED: 2 assertions failed and 2 passed (1.145s)

    

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15. h"ps://dequeuniversity.com/rules/axe/2.6/color-contrast
    

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16. Accessibility Tes8ng
    h"p://nightwatchjs.org
    h"ps://github.com/ahmadnassri/nightwatch-accessibility
    

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17. Visual Regression Tes8ng
    

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18. $ yarn test:e2e @tds/core-notification
    yarn run v1.5.1
    $ node scripts/e2e.js
    Started chromedriver
    [Components Spec] Test Suite
    ================================
    Running: @tds/core-notification
    ✖ Screenshots Match Failed for chrome_headless.png with a tolerance of 0%,
    actual was 1.07%. - expected "0" but got: "1.07"
    at Object.takeScreenshot (/Users/ryanoglesby/Projects/telus-digital/tds/e2e/
    commands/compareScreenshot.js:55:17)
    at Object.browser.saveScreenshot (/Users/ryanoglesby/Projects/telus-digital/
    tds/e2e/commands/compareScreenshot.js:38:16)
    at FSReqWrap.oncomplete (fs.js:153:20)
    FAILED: 1 assertions failed and 3 passed (3.314s)
    _________________________________________________
    TEST FAILURE: 1 assertions failed, 3 passed. (3.378s)
    

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19. Visual Regression Tes8ng
    

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20. Visual Regression Tes8ng
    

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21. Visual Regression Tes8ng
    

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22. Visual Regression Tes8ng
    h"ps://github.com/HuddleEng/Resemble.js
    

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23. Engineering for stability
    by crea(ng inten(onal APIs and

    tes(ng first and o5en.
    Engineering for scale ↔
    by automa(ng documenta(on and
    op(mizing package distribu(on.
    

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24. • Correct and trustworthy
    • Comprehensive
    • Component APIs (props, data types, allowed values)
    • Live examples
    Documenta8on must-haves
    React Styleguidist Storybook
    

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25. /**
    * A standard, branded clickable element for use in forms mainly.
    * @version 1.0.2
    */
    class Button extends React.Component {
    render() {
    // ...
    }
    }
    Button.propTypes = {
    /**
    * The HTML button type.
    * @see See [MDN](https://developer.mozilla.org/en-US/docs/Web/HTML/
    Element/button) for more info.
    */
    type: PropTypes.oneOf(['button', 'submit', 'reset']),
    /**
    * The style.
    */
    variant: PropTypes.oneOf(['primary', 'secondary', 'inverted']),
    /**
    * The label.
    */
    children: PropTypes.string.isRequired,
    }
    Button.defaultProps = {
    type: 'button',
    variant: 'primary',
    }
    

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26. Provide a function as the `onClick` prop to perform an action when
    clicked. **Avoid using a button if navigation
    is the primary action, as a [Link](#link) is more appropriate.**
    ### Best practices
    * Aim to use only one primary button per page
    * Keep the label short and able to fit on a single line
    * The label should clearly describe the action
    By default, Buttons will be displayed in the `primary` variant. Use
    primary buttons for the main action on a page or
    in a form.
    ```
    Submit
    ```
    Specify the `variant` to create a button for secondary actions.
    ```
    Find out more
    ```
    

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27. h"ps://tds.telus.com/components/index.html
    

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28. h"ps://www.npmjs.com/package/@telusdigital/tds
    

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29. import { Button } from '@telusdigital/tds'
    import '@telusdigital/tds/dist/index.css'
    class HelloWorldApp extends React.Component {
    render() {
    return (
    Hello world
    );
    }
    }
    export default HelloWorldApp
    

    {
    "name": "@telusdigital/hello-world-app",
    "version": “0.1.0",
    "description": "An app that says hello",
    "dependencies": {
    "@telusdigital/tds": "^1.0.0"
    }
    }
    

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30. import { Button } from '@telusdigital/tds'
    import '@telusdigital/tds/dist/index.css'
    class HelloWorldApp extends React.Component {
    render() {
    return (
    Hello world
    );
    }
    }
    export default HelloWorldApp
    

    {
    "name": "@telusdigital/hello-world-app",
    "version": “0.1.0",
    "description": "An app that says hello",
    "dependencies": {
    "@telusdigital/tds": "^1.0.0"
    }
    }
    “^2.0.0"
    .TDS_Button__primary___3Xb72 {
    /* ... */
    }
    .TDS_Button__secondary___2qhCP {
    /* ... */
    }
    .TDS_Text__base___2nt0g {
    /* ... */
    }
    .TDS_Box__spacing2___3Z6ro {
    /* ... */
    }
    

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31. @tds/box
    @tds/buDon
    @tds/buDon-link
    @tds/card
    @tds/checkbox
    @tds/chevron-link
    @tds/colours
    @tds/css-reset
    @tds/decora8ve-icon
    h"ps://lernajs.io
    

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32. h"ps://www.npmjs.com/org/tds
    

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33. • Consolidate the lint, build, test, and release process
    • Easier to coordinate changes across mul• Single place to report issues
    • Easier to generate documentaWhy a monorepo?
    

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34. import Box from '@tds/core-box'
    import Button from '@tds/core-button'
    class HelloWorldApp extends React.Component {
    render() {
    return (
    
    Hello world
    
    );
    }
    }
    export default HelloWorldApp
    

    {
    "name": "@telusdigital/hello-world-app",
    "version": “0.1.0",
    "description": "An app that says hello",
    "dependencies": {
    “@tds/core-box": “^1.0.2”,
    “@tds/core-button": "^1.1.0"
    }
    }
    

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35. h"ps://tds.telus.com
    h"ps://github.com/telus/tds-core
    It’s open source
    

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36. React
    CSS Modules
    ✅ jest + enzyme + enzyme-matchers
    nightwatch + nightwatch-accessibility (axe-core)
    resemble-js
    react-styleguidist
    lerna
    Key technology
    

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37. 
    Ryan Oglesby
    @ryanoglesby08
    hOps:/
    /ryanogles.by
    Engineering a Design System
    

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